Made of high quality chrome vanadium steel materials, surface sandblasting, strong rust and corrosion resistance, high temperature quenching treatment improves durability and durability. Product Design Hex design, 1/4 inch shank fits most corded or cordless motorized drills. Easy to install and disassemble, not easy to fall off during use. The set includes 14 hex socket bits: 5mm, 5.5mm, 6mm, 7mm, 8mm, 10 mm, 12 mm and 3/16 inch, 1/4 inch, 9/32 inch, 5/16 inch, 11/32 inch, 3/8 inch, 7/16 inch. Wide application suitable for household DIY, woodworking, auto parts, professional machinery, etc. Widely used in those hex tools, such as air wrenches, electric wrenches, air drills, electric drills, gun drills, hand wrenches, etc. Customer Service If you encounter any quality or usage problems you have, please feel free to contact us. We will reply to you as soon as possible and provide our customers with the best service.